My projects

I write soft­ware mostly for Mor­phOS and Ami­gaOS, (clas­sic Ami­gaOS 3.x). I've also
done a few small ap­pli­ca­tions for Win­dows. My pro­gram­ming lan­guage of choice is C,
I also have writ­ten code in C++, Lua, Amiga E and PHP, as well as M68k and PowePC as­sem­bler.

String To Float­ing Point Num­ber Con­ver­sion,
shows how to con­vert a tex­tual rep­re­sen­ta­tion of a float­ing point num­ber (in plain or sci­en­tific
no­ta­tion) into a num­ber bi­nary con­form­ing to IEEE754. The code is al­most a drop-in re­place­ment for
stan­dard atof() and str­tod() func­tions. It does not use the stan­dard C li­brary how­ever
and is also much shorter.

Notes on AES-256 Ci­pher Im­ple­men­ta­tion on Pow­erPC
Proces­sors, my at­tempt to code an op­ti­mized im­ple­men­ta­tion of this well known crypto­graphic
stan­dard for PPC proces­sors. I show the op­ti­miza­tion process step by step, start­ing from naive byte­wise
im­ple­men­ta­tion, through op­ti­miza­tion in C, using as­sem­bler and fi­nally Al­tiVec. Cur­rently this
ar­ti­cle is work in progress.

Peer-reviewed scientific publications

I've writ­ten them until given up my aca­d­e­mic ca­reer. Most of them is re­lated to dig­i­tal sig­nal
pro­cess­ing, es­pe­cially using Al­tiVec SIMD unit of Pow­erPC proces­sors.

A codec of speech based on the en­hanced TM­S320C5x DSK mod­ule, Konopko K., Kraszewski G. (1999). This paper de­scribes an in­ter­face, de­vel­oped by me in co­op­er­a­tion with K. Konopko. The in­ter­face con­nected a DSK mod­ule with TM­S320C50 proces­sor with a PC com­puter. It con­sisted of DSK in­ter­face board de­signed by me and an ISA card de­vel­oped by Mr. Konopko. He also wrote comm­ni­ca­tion soft­ware run­ning on Win­dows. We pub­lished the paper on 99' Sig­nal Pro­cess­ing Work­shop in Poz­nań (8 Oct 1999).

PCI bus bridge for MC 680x0 based com­puter sys­tem using PLD tech­nol­ogy, Kraszewski G. (2003). The paper de­scribes the "Prometheus" PCI bridge­board for Amiga 3000/4000 com­put­ers. It is a bridge in­ter­con­nect­ing asyn­chro­nous Amiga Zorro III ex­ten­sion bus with stan­dard PCI bus. It was de­signed using two MAX7128 PLD chips from Al­tera. It al­lowed for using sev­eral mod­els of PCI cards in Amiga com­put­ers. The paper was pre­sented on XII IEEE-SPIE Sym­po­sium on Pho­ton­ics and Web En­gi­neer­ing, held in Wilga near War­saw, on 22 to 25 May 2003. Then it has been pub­lished in Pro­ceed­ings of SPIE in 2004.

Fast FIR fil­ters for SIMD proces­sors with lim­ited mem­ory band­width, Kraszewski G. (2006). The paper demon­strates how re­or­ga­ni­za­tion of order of com­pu­ta­tions in a FIR fil­ter can in­crease com­pu­ta­tional ef­fi­ciency with­out re­duc­ing the num­ber of arith­metic op­er­a­tions. As a FIR fil­ter is usu­ally a mem­ory bound task for a SIMD proces­sor, low­er­ing num­ber of mem­ory ac­cesses per out­put sam­ple in­creases the speed of pro­cess­ing. I've pub­lished a the­ory be­hind it, as well as re­sults of prac­ti­cal ex­per­i­ments. Pre­sented on XI AES Sym­po­sium: New Trends in Audio and Video held on Białystok Uni­ver­sity of Tech­nol­ogy (20 to 22 Sep 2006).

Webpages I've developed and manage

In web de­vel­op­ment I be­lieve in sim­plic­ity in both graph­ics de­sign and server side pro­gram­ming. I use basic pop­u­lar web tech­nolo­gies: HTML, JavaScript, PHP, MySQL. My pro­jects are light­weight, clean and se­cure.

morphos-files.net, the Mor­phOS soft­ware repos­i­tory. I've pro­grammed the site, I'm also the main­tainer. Graphic de­sign is
mine too, ex­cept of the upper ban­ner graphic, which has been drawn by Prze­mysław Tkaczyk.

elektrownia.pb.edu.pl, a mon­i­tor­ing site of a hy­brid power plant (wind and solar). I've also writ­ten large parts of data ac­qui­si­tion back­end.